elbow jts Flashcards
humeroulnar jt is articulation of the
distal humerus with the promxial ulna
humeroradial jt is articulation of the
proximal radiaus with proximal ulna
3 major ligaments of elbow
ulnar (medial) collateral ligament
radial (lateral) collateral ligament
annular ligament
ulnar (medial) collateral ligament connects
humerus w/ ulna
radial (lateral) collateral ligament connects
humerus w/ radius
annular ligament connects
radius w/ ulna
collateral ligaments provide what?
support for stresses in frontal plane
ulnar (medial) collateral ligament provides support for stress that are what kind of forces?
valgus forces
radial (lateral) collateral ligament provides support for stress that are what kind of forces?
varus forces
lateral =
varus
medial =
valgus
The annular ligament provides
stability for the radius, securing it to ulna
The elbow jt complete is a compound what joint that consists of what 2 articulations?
synovial jt w/ 2 articulations: humeroulnar and humeroradial
The elbow joint is what w/ proximal RU jt?
continuous
The proximal RU jt being continuous w. elbow jt allows
radial head to rotate during pronation and supination of forearm
What does distal humerus articulate w/ ? What are they enclosed by?
distal humerus articulates with both proximal ulna and radius, which are enclosed by one capsule and share single synovial cavity
Laterally, the capitulum of humerus articulates w/ head of radius to form what jt ?
humeroradial jt
Medially, the trochlea of humerus articulates w/ trochlear notch of ulna to form what jt ?
humeroulnar jt
what joint has a jt capsule that is continuous w/ that of humeroulnar and humeroradial jts, and is articulation of radial head w/ radial notch of ulna
PROXIMAL radioulnar jt
What kind of jts are the humeroulnar and humeroradial jt ? What kind of muscle action does this yield?
hinge jts that flex and extend elbow in sagg plane
During saggital motion of elbow, what happens?
trochlear notch of humerus slides into the trochlear groove of the ulna
Upon elbow full flexion, what occurs ?
the coronoid process of ulna approximates the coronoid fossa of humerus
At full ext, what what happens?
the olecranon process of ulna hit the olecranon fossa, thereby enhancing stability of elbow in full ext
what kind of jt is proxoimal RU jt?
pivot jt
proximal RU jt permits what>
axial rot of radial head during supination and pronation of forearm
elbow ROM supination and pronation
80-90 degreee
Anterior muscles of elbow muscle action
flex elbow
what are the ant muscles of elbow?
biceps, brachilais, and brachioradialis
long head of biceps origin
supraglenoid tubercle of scapula
short head of biceps origin
coracoid process of scapula
long and short heads of biceps insertion
tuberosity of radius
biceps is a strong what and does what muscle action of elbow?
strong supinator and flexes elbow most effectively when forearm supinated
long head biceps assists in what muscle action of shoulder?
shoulder flexion
How do you effectively train biceps>
elbow flexion and forearm supination
WHAT MUSCLE IS elbow flexor workhorse?
brachialis
What pronates forearm?
pronator quadratus (stronger) pronator teres
posterior muscles of elbow do what muscle action
extension of arm
posterior muscles
ticeps and aconeus
describe triceps
3 head, 2 jt muscles that acts on shoulder and elbow
long head of triceps origin
infraglenoid tubercle of scapula
medial and lat heads of triceps origin
upper humerus
All 3 heads of triceps insertion
olecranon of ulna
triceps is what muscle action
main elbow extensor
aconeus provides
minor assistance to triceps in elbow flexion
aconeus
a small muscle that adds stability to posterior elbow jt